The present invention relates to pressure sensitive switches and more particularly to pressure sensitive switches which provide an indication when a fluid pressure reaches a predetermined limit.
There are many applications wherein it is essential that fluid pressure levels be maintained within a predetermined pressure range. The fluid pressure must not decrease below a minimum limit nor increase beyond a maximum limit. The oil pressure of an automobile is a good example of such an application.
In order to monitor fluid pressures and to provide an indication when the fluid pressures are either below or above a safe operating range, pressure sensitive switches have been devised. Such prior pressure sensitive switches have incorporated a number of movable parts which lend to their complexity and unreliable operation over an extended period of time. Such switches may become unreliable because the number of movable parts may lock in either an open or closed position. The cumulative effect is that prior switches suffer eventual degraded accuracy and potential non-operability. Also, prior art pressure sensitive switches have not responded to the need of sensing multiple pressure while maintaining simplicity of design and reliable operation.
It is therefore a general object of the present invention to provide a new and improved pressure sensitive switch.
It is another object of the present invention to provide a new and improved pressure sensitive switch for detecting when a fluid pressure reaches a predetermined limit.
It is a still further object of the present invention to provide a new and improved pressure sensitive switch which affords extremely high levels of reliability even after extended periods between switch closures.
It is a still further object of the present invention to provide a new and improved pressure sensitive switch which provides sensitive and highly reliable operation notwithstanding adverse environmental conditions such as vibration, shock, and wide temperature excursions and which is capable of sensing a multiplicity of pressures.